Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
641 FXUS62 KKEY 120917 AFDKEY Area Forecast Discussion National Weather Service Key West FL 517 AM EDT Wed Jun 12 2024 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 517 AM EDT Wed Jun 12 2024 Last night`s sounding sampled a very tropical-looking profile, with well above normal moisture, high CAPE values, and a high freezing level. This environment allowed for the development of squalls that produced measured winds gusts of between 40-50 mph. This stronger convective activity has since weakened and mainly stratiform rain is being detected by KBYX radar this morning aside from some showers over the Florida Bay. Some of these showers have presented occasions of weak rotation earlier, which is somewhat unexpected in this environment. Over the past 24 hours, MRMS estimates that all of the Keys received between 0.5-1.5" of rainfall. Just to our north across South Florida, estimates were anywhere between 2-11" of rainfall. Most of our rainfall was generally light to moderate, but a few squalls joined the mix throughout the day. Overcast conditions combined with persistent rainfall has allowed for temperatures to drop into the upper 70s to lower 80s this morning, however, southerly flow has brought in dew points as high as the lower 80s this morning. This has made for quite a muggy morning outside of any areas receiving rainfall. The same general synoptic set up we have seen the past two days with broad troughing across the Gulf, a low level ridge extending from the western North Atlantic across the region, and a stalled front across Northern Florida will remain in place through Friday, so have maintained well above normal rain and thunder chances through at least Friday night, with mention of heavy rainfall possible. Deep tropical moisture will continue to stream across the region, but will again be trapped across Central and South Florida by the stalled frontal boundary across northern Florida. Uncertainties remain in the coverage and intensities of any possible convection across the Florida Keys, and just as we saw yesterday, global models keep the best environment to our north. This does not mean we are out of the woods by any means, but does mean that there will once again there will likely be a sharp rainfall gradient across our area, with the highest rainfall values being measured to our north. Some guidance is hinting at a slight southward shift in the best moisture and environment Thursday and Friday, so we will continue to monitor this trend. The Weather Prediction Center has the Florida Keys in a Slight Risk of excessive rainfall through the end of the work week. By Saturday, an expansive ridge across the North Atlantic will build across the region and finally shove the deep tropical moisture west. The pressure gradient across our area will gradually tighten through the weekend, which will lead to a period of breezy conditions. At the same time, rain chances will finally return to near to slightly above normal beginning Saturday night. Diminishing cloud cover will allow temperatures to climb back to near 90 degrees and we will return to our regularly scheduled toasty conditions. && .MARINE... Issued at 517 AM EDT Wed Jun 12 2024 Small Craft Should Exercise Caution until winds decrease in the Straits of Florida, Hawk Channel, and SE Gulf. From synopsis, The pattern for the remainder the week will feature weak high pressure over the western North Atlantic and a frontal boundary stalled over northern Florida. Although, the main weather maker will be a large cyclonic gyre centered over Central America. As such, mainly moderate breezes and an extended period of unsettled weather featuring thundery squalls will persist today through Friday night. Rain and thunder chances will decrease gradually starting Saturday. Breezes will begin to freshen Saturday night into Sunday. && .AVIATION... (06Z TAFS) Issued at 517 AM EDT Wed Jun 12 2024 VFR conditions are expected for most of the TAF period over EYW and MTH. However, widespread rain and thunderstorms are forecast for the Florida Keys and adjacent waters and the environment supporting heavy rain remains. MVFR CIGs are possible during the day after shower redevelopment, and the heaviest thunderstorms could produce LIFR VIS. TEMPOs for IFR or LIFR conditions are absent from the morning TAFs due to the uncertainty in where and when thunderstorms will develop. Prevailing near-surface winds will be southerly near 10 knots. && .CLIMATE... On this day in Keys weather history, in 2013 the daily record rainfall of 3.03" was measured at Key West. Notably in 2002, at John Pennekamp State Park, a daily rainfall record of 5.29" was measured. Rainfall records for Key West date back to 1871. && .PRELIMINARY POINT TEMPS/POPS... Key West 87 80 87 79 / 70 70 70 70 Marathon 87 80 87 79 / 70 70 80 70 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...Flood Watch through this evening for FLZ076>078. GM...None. && $$ Public/Marine/Fire...NB Aviation/Nowcasts....AJP Data Acquisition.....AJP Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest